Particularly throughout the last decade, Reactive Oxygen Species (ROS) and the biology of free radicals have attracted great interest in the biomedical research community. This has led to an exponential increase in the number of studies focused on their role in cellular defense, cell signaling, apoptosis, aging, hypertension, atherosclerosis, oxygen sensing, inflammation and fibrosis. This area of research is particularly difficult because various ROS such as superoxide, hydrogen peroxide, hypochlorous acid, hydroxyl radical and nitric oxide are short lived molecules that react with proteins, lipids, nucleic acids and one another. This occurs within cellular microdomains through complex chemical reactions. Particularly difficult issues present themselves to investigators because methods for detection of ROS are plagued with problems of poor specificity. The molecular biology is also complex because cells have evolved much machinery dedicated to generation, conversion and consumption of ROS. These macromolecules include multiple isoforms of NADPH oxidases, superoxide dismutases, catalase and hemoxygenase. Furthermore, exogenous substances such as Vitamin C and D can act in concert with those cellular enzymes to scavenge free radicals. This conference has been designed to bring together world experts to provide talks that logically progress from definition of ROS to their detection, cellular machinery and various biological roles. Our general goal is to provide partial support for young scientists attending the juxtaposed American Society of Nephrology meeting to also attend this two day conference. Attendance of young scientists insures that the information will be translated into future studies that elucidate the role of ROS in kidney diseases and treatment thereof. [unreadable] [unreadable] [unreadable]